There are a large variety of substances which become luminescent or light emitting when stimulated or excited by suitable electromagnetic radiation such as lamplight or sunlight. The materials after absorbing the appropriate radiation continue to emit light or luminescence after the source of the existing energy is removed. When light is emitted only during the period of excitation, then the term is generally referred to as flourescence. When the light emission or the after-glow is delayed after the exciting energy is shut off then the delayed light emission is generally called phosphorescence. There has been a development of a large number of inorganic phosphors which act as phosphorescing materials. The materials are comprised of a host material or matrix compound such as the silicates, phosphates, sulfides, alkylhalides and the oxides of calcium, magnesium, barium and zinc. There are activators incorporated into these materials which can confer luminescent properties upon these host materials. Frequently used activators are magnanese, copper, silver, thallium, lead, cerium, chromium, titaniam, antimony and tin. Magnanese is a particularly effective activator in a wide variety of host materials when incorporated in amounts ranging from small traces up to the order of several percent. The color of a light emitted from these magnanese activated phosphorers is in the green or orange spectral regions.